The present invention relates to a photosensitive detector for detecting luminous flashes, and to a mosaic of photosensitive detectors including a plurality of such photosensitive detectors, as well as to several applications of said mosaic of photosensitive detectors.
A particularly interesting application of a mosaic of photosensitive detectors relates to a device for detecting, and possibly locating, a luminous source emitting specified luminous flashes.
The major drawback, when implementing such a device, resides in the presence, in addition to the luminous flashes emitted by the luminous source which it is desired to detect, of strong illumination, especially that from the sun and from flares, which forms luminous background noise, often making it very difficult to detect said sought-after luminous flashes.
It may even happen that the luminous background noise is so large that it almost completely swamps the luminous signal which it is desired to detect.
It is noted that the document FR-A-2 583 523, which discloses a system which includes photosensitive detectors arranged in rows and columns in matrix form, for locating a mobile emitting luminous flashes, makes provision, in order to remedy this drawback, for associating a comparison device with said system. This comparison device makes it possible to record the background noise, either just before or just after detection, and to subtract this recorded background noise from the detected signal containing the sought-after luminous flashes.
However, the frequency of detection is reduced for this system. Thus, each duration of detection demands an identical duration for the recording of the background noise which is to be subtracted and the subtraction time is lengthy since this subtraction is not incorporated with detection and is done only after the reading of the images.